DE69802529T2 - olefin - Google Patents

Abstract

Olefins such as ethylene and alpha -olefins may be (co)polymerized using preformed catalysts containing selected transition metals, especially late transition metals, complexed to selected ligands. These performed catalysts are preferably particulate solids, and may be used for polymerizations in liquid media or the gas phase.

Description

FIELD OF INVENTION

Polymerization processes involving polymerization catalysts containing transition metals bound to selected ligands and supported and/or preformed are described. In some cases, this enables the use of more economical polymerization processes, such as gas phase or liquid slurry polymerizations.

TECHNICAL BACKGROUND

The polymerization of olefins, such as ethylene and/or propylene, is a very important industrial process that is used on a huge scale throughout the world. A significant factor in this production is the polymerization process used, which is crucial in determining the properties of the polymer produced but also its cost.

In some polymerization processes, the polymerization catalyst can be prepared in situ, or it can be prepared in full or in part ahead of time. The catalyst or its components can be added to the polymerization itself, or they can be added "associated" with solid materials (often referred to as supports). Other variations are possible, and the type of polymerization process that can be used is determined in part by the nature of the catalyst system used.

The shape of the catalyst system is therefore crucial. For example, in gas phase or liquid slurry polymerization systems, the catalyst is often preformed and usually on a solid support, so that solid granules of "catalyst" and later polyolefin are present in the polymerization, which reduces blocking of the reaction apparatus. New forms of polymerization catalysts for olefins are therefore constantly being sought.

A recent development in olefin polymerization has been the discovery that selected complexes of transition metals and especially later transition metals catalyze the polymerization of olefins, see for example WO 96/23010 and WO 97/02298. It has been discovered that these catalyst systems can be converted to and used in various formulas.

SUMMARY OF THE INVENTION

The present invention relates to a catalyst for the polymerization of olefins prepared by a process comprising:

(a) Contact at a temperature of -100ºC to +200ºC:

a first compound W which is a neutral Lewis acid capable of splitting off either Q⁻ or S⁻ to form WQ⁻ or WS⁻, provided that the anion formed is a weakly coordinating anion; or a cationic Lewis or Bronsted acid whose counterion is a weakly coordinating anion;

a second compound of the formula:

and a first polymerizable olefin, in which formula is:

M Ni or Pd;

R² and R⁵ are each independently hydrocarbyl or substituted hydrocarbyl, provided that the carbon atom attached to the imino nitrogen has at least two carbon atoms attached thereto;

R³ and R⁴ are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl, or R³ and R⁴ are taken together hydrocarbylene or substituted hydrocarbylene to form a ring;

Q alkyl, hydride, chloride, iodide or bromide;

S alkyl, hydride, chloride, iodide or bromide;

as well as

(b) isolating a polymer formed under (a) without exposing the polymer to a substance or condition that would deactivate the active polymerization sites present in or on the polymer.

The invention also relates to the process for the polymerization of olefins comprising the step of contacting the catalyst according to the present invention with a second polymerizable olefin at a temperature of -100° to +200°C.

DETAILS OF THE INVENTION

Certain groups may be present in the polymerization processes and catalyst compositions described herein. By "hydrocarbyl" is meant a monovalent radical containing only carbon and hydrogen. By "saturated hydrocarbyl" is meant a monovalent radical containing only carbon and hydrogen and free of carbon-carbon double bonds, triple bonds and aromatic groups. By "substituted hydrocarbyl" is meant herein a hydrocarbyl group containing one or more (types) of substituents that do not interfere with the function of the catalyst system for polymerization. Suitable substituents include: halogen, ester, keto(oxo), amino, imino, carboxyl, phosphite, phosphonite, phosphine, phosphinite, thioether, amide, nitrile and ether. Preferred substituents are halogen, ester, amino; Imino, carboxyl, phosphite, phosphonite, phosphine, phosphinite, thioether and amide. By (substituted) "hydrocarbylene" is meant a group which is analogous to hydrocarbyl except that the radical is divalent. By "benzyl" is meant the radical C₆H₅CH₂-, while substituted benzyl is a radical in which one or more hydrogen atoms are replaced by a substituent group (which may include hydrocarbyl). By an "aryl portion" is meant a monovalent group whose dangling bonds extend from a carbon atom of an aromatic ring. The aryl portion may contain one or more aromatic rings and may be substituted by inert groups. By "phenyl" is meant the radical C6H5-, while a "phenyl portion" or "substituted phenyl" is meant a radical in which one or more hydrogen atoms are replaced by a substituent group (which may include hydrocarbyl). Preferred substituents for substituted benzyl and phenyl include those mentioned above for substituted hydrocarbyl plus hydrocarbyl. Unless otherwise stated, hydrocarbyl, substituted hydrocarbyl and all other groups containing carbon atoms, such as alkyl, preferably contain 1 to 20 carbon atoms.

Noncoordinating ions are mentioned and are useful herein. These anions are well known to those of ordinary skill in the art, see, for example, W. Beck, et al., Chem. Rev., Vol. 88, pp. 1405-1421 (1988), and S.H. Strauss, Chem. Rev., Vol. 93, pp. 927-942 (1993), both of which are hereby incorporated by reference. In these references, the relative coordinating abilities of such noncoordinating anions are described, see Beck on page 1411 and Strauss on page 932, Table III. Useful noncoordinating anions include SbF6-, BAF, PF6-, or BF4-. where BAF is tetrakis[3,5-bis(trifluoromethyl)phenyl]borate.

A neutral Lewis acid or a cationic Lewis or Bronsted acid whose counterion is a weakly coordinating anion are also present as part of the catalyst system. By a "neutral Lewis acid" is meant a compound which, as a Lewis acid, is capable of cleaving Q- or S- (or alternatively both or each, since they may be the same) from (I) to form a weakly coordinating anion. The neutral Lewis acid is initially uncharged (i.e. non-ionic). Suitable neutral Lewis acids include SbF5, Ar3B (wherein Ar is aryl) and BF3. By a cationic Lewis acid is meant a cation having a positive charge, such as Ag+, H+ and Na+.

In those cases where (I) (and similar catalysts requiring the presence of a neutral Lewis acid or a cationic Lewis or Bronsted acid) does not contain an alkyl or hydride group already attached to the metal (i.e. neither Q nor S is alkyl or hydride), the neutral Lewis acid or a cationic Lewis or Bronsted acid alkylates the metal or adds a hydride to it, i.e. it causes an alkyl group or hydride to be attached to the metal atom, or a separate (from W) compound is added to add the alkyl group or hydride group.

A preferred neutral Lewis acid capable of alkylating the metal is a selected alkylaluminum compound such as R93Al, R92AlCl, R9AlCl2, R93Al2Cl3 and "R9AlO" (alkylaluminoxanes) where R9 is alkyl containing 1 to 25 carbon atoms and preferably 1 to 4 carbon atoms. Suitable alkylaluminum compounds include methylaluminoxane (which is an oligomer having the general formula [MeAlO]n), (C2H5)2AlCl, C2H5AlCl2, (C2H5)3Al2Cl3, and [(CH3)2CHCH2]3Al, with methylaluminoxane being a preferred alkylaluminum compound. Metal hydrides such as NaBH4 can be used to attach the hydride groups to the metal M.

In the compounds such as (I), an α-diimine of the formula

as a ligand. In all cases where (II) appears herein, including as a ligand, preferably R² and R⁵ are each independently hydrocarbyl, provided that the carbon atom attached to the imino nitrogen atom has at least 2 carbon atoms attached thereto; and R³ and R⁴ are each independently hydrogen, hydrocarbyl, or R³ and R⁴ are taken together hydrocarbylene to form a ring. Some useful combinations and/or individual moieties for R², R³, R⁴ and R⁵ are shown in Table I. TABLE 1

a -CMe2 CH2 CMe2 -.

*In Table I and elsewhere herein, the following abbreviations are used: Me = methyl; Et = ethyl; Cl = chlorine; Br = bromine; i-Pr = isopropyl; Ph = phenyl; and An = 1,8-naphthylylene,

To indicate substitution on a phenyl ring, the nomenclature is abbreviated, with the number of ring positions indicating how many substituents are on the ring. For example, 4-Br-2,6-MePh denotes 4-bromo-2,6-dimethylphenyl.

Compounds other than in (II) can be used as ligands for the Ni atom in (I). Compounds such as Ar¹Qn(III); R⁸R¹⁰N-CR²⁸R²¹(CR⁶R⁷)m-NR⁸R¹⁰ (IV);

in which are:

Ar¹ is an aromatic moiety with n free bonds or diphenylmethyl;

Each Q is -NR²⁵R⁴³ or -CR⁹=NR²⁶;

n 1 or 2;

E 2-thienyl or 2-furyl;

each R²⁵ is independently hydrogen, benzyl, substituted benzyl, phenyl or substituted phenyl;

each R⁹ is independently hydrogen or hydrocarbyl;

and each R²⁶ is independently a monovalent aromatic moiety;

m is 1, 2 or 3;

R⁴ is hydrogen or alkyl;

each R²⁰, R²¹, R⁶ and R⁷ are independently hydrogen, hydrocarbyl or substituted hydrocarbyl;

each R⁸ is independently hydrocarbyl or substituted hydrocarbyl containing 2 or more carbon atoms;

each R¹⁰ is independently hydrogen, hydrocarbyl or substituted hydrocarbyl;

Ar² is an aryl moiety;

R¹², R¹³ and R¹⁴ each independently represent hydrogen, hydrocarbyl, substituted hydrocarbyl or an inert functional group;

R¹¹ and R¹⁵ are each independently hydrocarbyl, substituted hydrocarbyl, or a functional group whose Es is about -0.4 or less;

each R¹⁶ and R¹⁷ independently represents hydrogen or acyl containing 1 to 20 carbon atoms;

Ar³ is an aryl moiety;

R¹⁵ and R¹⁵ are each independently hydrogen or hydrocarbyl

Ar4 is an aryl moiety;

Ar²¹ and Ar⁶ are each independently hydrocarbyl;

Ar⁷ and Ar⁸ each independently represent an aryl moiety;

Ar⁹ and Ar¹⁰ each independently represent an aryl moiety or -CO₂R²⁵, wherein R²⁵ is alkyl having 1 to 20 carbon atoms;

Ar¹¹ is an aryl moiety;

R⁴ is hydrogen or hydrocarbyl;

R4² hydrocarbyl or -C(O)-NR4¹-Ar¹¹;

R⁴⁴ is aryl;

R²² and R²³ are each independently phenyl groups substituted by one or more alkoxy groups, wherein each alkoxy group contains 1 to 20 carbon atoms; and

R²⁴ is alkyl containing 1 to 20 carbon atoms or an aryl moiety.

In the compounds listed immediately above, Es denotes the steric effect of a group. The steric effect of various moieties has been quantified using a parameter called "Es," see R.W. Taft, Jr., J. Am. Chem. Soc., vol. 74, pp. 3120-3128 (1952) and M.S. Newman, "Steric Effects in Organic Chemistry," John. Wiley&Sons, New York, 1956, pp. 598-603. The Es values for the present problems are those described in those publications. If the value of Es for any group is not known, it can be determined by the methods described in those publications. For the problems herein, the value specified for hydrogen is the same as for methyl. Preferably, the total Es value for the ortho substituents (or other substituents immediately adjacent to the -OH group) in the ring is about -1.5 or less, and more preferably about -3.0 or less. Thus, in a compound such as 2,4,6-tri-tert-butylphenol, only the Es values for the 2- and 6-substituted tert-butyl groups are applicable.

In addition to the above ligands which can be used in compounds similar to that of (I), metals other than Ni can be used. These metals include: Ti, Zr, Sc, V, Cr, any rare earth metals, Fe, Co and Pd. In those cases where the metal is in an oxidation state other than the +2 oxidation state, the appropriate number of Q and S groups are present to ensure that (I) is a neutral representative. The preparations of the various ligands and of the compound (I) with their various combinations can be found in WO 96/23010 and 97/02298, both of which are incorporated herein by reference. In (I), M is preferably Ni.

The temperature at which the preparation of the catalyst and the polymerization are carried out, i.e. steps (a) and (c), respectively, is about -100°C to about +200°C, and preferably about -20°C to about +80°C. The pressures at which either or both of the steps are carried out with a gaseous olefin are not critical, with atmospheric pressure to about 275 MPa or above being a suitable range. In the case of a liquid monomer, the monomer can be used neat or diluted with another liquid (solvent) for the monomer. The ratio of W:(I) is preferably about 1 or more, and more preferably about 10 or more when only W (no other Lewis acid catalyst) is present. Further details of these ratios can be found in WO 96/23010 and 97/02298.

Although the first (a) step of the processes herein can be carried out in liquid phases or gas phases, it is preferred to carry them out in the liquid phase. If the monomer (olefin) is a liquid, this can be done in the neat olefin, or the olefin can be diluted with another liquid and preferably a solvent. If the monomer is a gas, a material that is liquid at process conditions (temperature and pressure) can be used. Preferably, the liquid present, whatever it is, dissolves at least to some extent all of the reactants present, i.e. (I), W and the olefin. Preferably, the product polymer does not necessarily have to be soluble in the liquid medium (see below).

The polymer formed in (a) can serve as the support for the active polymeric polymerization catalyst and for other materials that receive the polymer formed in (a) such as alumina, silica (including partially dehydrated silica gels), a clay, a zeolite, MgO and TiO2 may also be present. In many cases, the polymer formed in (a) will encapsulate or "stick" to any solid particulate support material present, and preferably the polymer will just fill any pores or irregularities in the surface of the solid support.

The polymer formed in (a) and/or (c) may be a homopolymer or a copolymer, and/or the polymer(s) formed in (a) and (c) may be the same or different. The monomers useful in (a) and (c) include ethylene, propylene, other α-olefins of the formula R50CH=CH2, where R50 is n-alkyl containing from 2 to about 20 carbon atoms, cyclopentene, norbornene, substituted cyclopentenes, styrene and substituted styrenes, and substituted norbornenes. Preferred monomers are ethylene, propylene and cyclopentene, with cyclopentene being more preferred. When cyclopentene is polymerized in (a), the liquid medium is preferably cyclopentene (and any other liquid reactants).

The polymer formed in (a), which is an active catalyst of olefin polymerization, can be separated in any manner as long as it is not exposed to substances or conditions which destroy and preferably do not substantially reduce its catalytic polymerization activity. Exposure to one or more of water, oxygen and alcohols, as well as elevated temperatures, can cause the catalytic activity to decrease. However, storage of the active polymeric polymerization catalysts described in the examples in a drying oven at -30°C for one week does not appear to significantly reduce the catalytic activity. If the catalytic activity decreases, it can occasionally be restored at least in part by adding W to the polymeric polymerization catalyst immediately before or simultaneously with the addition of the olefin to be polymerized in step (c).

The polymeric polymerization catalyst produced in (a) can be separated by removing the liquid(s) present to isolate the polymer. These liquids can be removed simply by applying a vacuum to the system (or heat if necessary, but see below). If the polymeric polymerization catalyst is not soluble in the liquid, the liquid can be decanted from the polymer, or the polymer (if it is a "solid") can be filtered from the liquid. If the polymer (a) is produced in a gas phase polymerization, it only needs to be separated from the gaseous olefin.

When the polymeric polymerization catalyst is used in (c), it is preferably in particulate form and more preferably of small particle size. A useful particle size (especially for polymerization in the gas phase or in liquid slurry) is about 20 to 50 micrometers and preferably about 20 micrometers, approximately spherical in shape being desirable. This is most easily achieved when the polymer produced in (a) is below its glass transition temperature and/or melting point while being produced and preferably maintained below that temperature before being used as a polymerization catalyst. When this is the case and the polymerization in (a) is in the liquid or gas phase Phase, the polymeric polymerization catalyst will often be obtained as a particulate solid.

Since the "target" polymer is the polymer ultimately produced in (c), it is obvious that the proportion of polymer produced in (a) is relatively small compared to the total amount of polymer produced in (a) and (c). Therefore, it is preferable to produce relatively small amounts of polymer in (a) in order to obtain a polymeric polymerization catalyst that is easy to handle. It is also preferable to ensure that the polymer produced in (a) breaks down during or after the polymerization in (c) so that only very small particles of the polymer produced in (a) are present in the final polymer matrix.

Active polymerization catalysts capable of initiating the polymerization in step (a) can also be prepared by other methods, such as by in situ generation of the metal complex of (II) (or other ligands) while an active catalyst is being generated. Such methods for generating active catalysts with the ligands and metals as described herein can be found in WO 96/23010 and 97/02298, both of which are hereby incorporated by reference. Similarly, the polymerizations set out in (c) herein to produce the "targeted" products can also be carried out as described in those patent applications. These applications also describe which monomers and monomer combinations can be used with which catalysts.

A particulate active polymerization catalyst can also be prepared by coating or otherwise adhesively bonding (depending on the support used, the "coating" may be by absorption, adsorption or actual chemical bonding between the compound and the solid support) nickel or other transition metal mentioned above, which is a complex of any of the aforementioned ligands, to a solid support such as alumina or silica (or any of the aforementioned) or a polymer such as polyethylene. This type of catalyst can be prepared simply by immersing the support in a solution of the compound and evaporating the solvent. This nickel compound (or other transition metal compound) is capable of polymerizing olefins on its own (without any cocatalysts). These compounds, such as certain pi-allyl complexes, and their preparation were described in WO 96/23010 and 97/02298.

On the other hand, compounds such as in (I) and other types of compounds (see WO 96/23010 and 97/02298) which are active polymerization catalysts can be coated on a solid support (and can chemically react with this support to form a bond with this support) with a cocatalyst such as W (which is an alkylaluminium compound or another Lewis acid such as B(C6F5)3) such as mentioned above, then placed in the presence of the olefin(s) to be polymerized and the cocatalysts such as an alkylaluminium compound and the polymerization starts.

Conversely, compound W can be applied to a support (often reacting with the support), after which (I) or a similar compound is added simultaneously with the addition of the polymerizing olefin or before. This also results in an active polymerization system. If there is another component for the polymerization system, such as another Lewis acid e.g. tris(pentafluorophenyl)borane, this can be added at this point (for example to the solvent to which the carrier, compound (I) and W have already been added).

Other catalysts that can be used in the polymerization systems described herein are Ni catalysts for the polymerization of norbornene and substituted norbornenes, see, for example, WO 95/14048, which is hereby incorporated by reference. In these catalysts, a soluble Ni salt such as Ni(acetylacetonate)2 and methylaluminoxane are reacted to produce an active catalyst species that polymerizes norbornenes. The polynorbornene produced can itself act as a support, or the polymerization can occur in the presence of another solid support, such as silica, to produce a polymeric polymerization catalyst.

In any of the above methods, a support can be chosen to "provide" relatively noncoordinating anion X. Such a support can be a clay such as montmorillonite.

The above polymerization catalysts, regardless of how they are prepared, are useful in polymerization in liquid media, in suspension or in solution and are especially useful in so-called gas phase or liquid slurry olefin polymerizations. It may also be useful when the polymerizations are carried out in the gas phase to have inert particulate solids present to absorb the heat of polymerization. They can be used in batch, semi-batch and continuous polymerization processes.

In the "Examples" certain α-diimine ligands are used and identified by letters. These ligands are listed below:

The following abbreviations were used in the examples:

ICP Inductively Coupled Plasma Spectroscopy

MAO Poly(methylaluminoxane)

TO Conversion in moles of polymerized olefin per mole of transition metal compound

PMAO see MAO

In the "Examples," branching is reported as a number of methyl groups per 1000 total (including those in the branches) methylene carbon atoms in the polymer. These have not been corrected for end groups.

In Tables 2, 3 and 4, the yields given are the total amount of solids obtained including any catalytic residues (and polymer from the catalyst) present in the product.

EXAMPLES 1-22 PRODUCTION OF SUPPORTED CATALYST

The following general procedure was used to prepare the supported polycyclopentene catalysts of these examples:

Inside a nitrogen-filled oven, 0.04 mM catalyst complex (I) [(α-diimine)NiBr₂] was added to 5 ml of anhydrous cyclopentene (when MAO was used as cocatalyst, 2 ml of anhydrous toluene was also added). The reaction mixture was quenched to -30°C. The desired cocatalyst was added and the solution was allowed to warm to room temperature while shaking vigorously. The reaction mixture was shaken for 5 hours, after which it was filtered under nitrogen, washed once with toluene and then three times with pentane and dried under vacuum. The separated supported catalyst was stored in the oven at -30°C. The details of each catalyst preparation are summarized in Table 2. TABLE 2

*PMAO, Akzo 9.5% by weight in toluene

** Equivalents based on added Ni

EXAMPLES 23-43 ETHYLENE POLYMERIZATION AT 35-70 kPa ETHYLENE PRESSURE

The following general procedure was used to test the catalysts of Examples 1 to 22 for activity for ethylene polymerization at 35-70 kPa ethylene pressure:

The catalyst was weighed into a Schlenk flask in a nitrogen-filled dry box (within 48 hours of preparation). Anhydrous pentane (10 mL) was added. The flask was capped, removed from the dry box and flushed with ethylene for 1 minute with stirring before placing under 35-70 kPa ethylene pressure. Polymerization was allowed to proceed for 16 hours, after which the reaction was quenched by addition of MeOH/10% HCl and the resulting solid polymer was filtered, washed sufficiently with MeOH, acetone and then dried under vacuum. The degree of branching of the resulting polyethylene was characterized by proton NMR. The polymerization results are summarized in Table 3. TABLE 3

EXAMPLES 44-58 ETHYLENE POLYMERIZATION AT 580 kPa ETHYLENE PRESSURE

The following general procedure was used to test the catalysts prepared in Examples 1 to 22 for activity for ethylene polymerization at 580 kPa ethylene pressure.

The catalyst was weighed into a glass insert inside a nitrogen-filled dry box (within 4 hours of preparation). Anhydrous benzene, a liquid inactivated solvent, was added to act as a heat transfer agent, and the insert was placed in a freezer at -30ºC for 30 minutes to ensure that all benzene was properly frozen. The cold insert was capped, removed from the dry box, and placed under 580 kPa ethylene pressure. After it reached room temperature, it was shaken for 18 hours. The resulting polymer was separated by filtration, washed with MeOH and then with acetone, and dried under vacuum. The polymerization results are summarized in Table 4. TABLE 4

EXAMPLE 59 POLYMERIZATION OF ETHYLENE USING VARIOUS DILUENTS

The supported catalyst was prepared in a nitrogen-filled glove box by adding 0.16 mM of the nickel dibromide complex of ligand B to 20 mL of anhydrous cyclopentene and BmL of anhydrous toluene. The mixture was quenched to -30ºC and MAO (5.2 mL) added. The catalyst solution was allowed to warm to room temperature and stirred for 5 hours, after which the solid supported catalyst was filtered, washed once with toluene and three times with pentane and dried under vacuum. The solid was stored at -30ºC. Yield = 3.55 g %Al (ICP) = 4.43%, %Ni (ICP) = 0.17%.

A 0.20 g portion of the catalyst (0.00579 mM Ni) was weighed into a glass insert inside a nitrogen-filled glove box (immediately after preparation). An anhydrous liquid inactivated solvent or a solid diluent (dried to remove water by heating under N2) was added to act as a heat transfer agent. The insert was capped, removed from the oven, and placed under 580 kPa ethylene pressure. It was then shaken for 18 hours. The resulting polymer was separated by filtration (due to liquid diluents), flotation (Teflon® 9B polytetrafluoroethylene, available from EI Du Pont de Nemours&Company, Wilmington, DE, USA), dissolution of the diluent (MgCl2) in water, or Soxhlet extraction of the soluble polymer with chlorobenzene. The polymerization results are summarized in Table 5. TABLE 5

*SiO2, PQ Corp. (MSI340), silylated trimethylchlorosilane

EXAMPLE 60

In a nitrogen-filled oven, silica-supported MAO (from Akzo Nobel, 13.4 wt% Al on silica, 0.773 g) was added to the complex [(α-diimine)NiBr2] (0.048 g), where the α-diimine is in H form, in 10 mL of anhydrous toluene. The mixture was shaken for 20 minutes, after which it was filtered and washed repeatedly with toluene until the washings were colorless. The final product was dried under vacuum for 15 minutes and then stored in an oven at -30°C.

On the same day, 0.096 g of the supported catalyst in 50 mL of anhydrous cyclohexane was added to a 100 mL Parr® reactor. The suspension was stirred under ethylene (1.17 MPa) for 43 minutes while the temperature was increased from 30°C to 45°C. The reaction was stopped by adding MeOH and the polymer product was filtered, washed with MeOH and dried. Yield = 9.11 g of polyethylene beads. No fouling of the reactor was observed.

After storing the catalyst at -30°C for 10 days, the reaction described above was repeated. Yield = 14.32 g of polyethylene beads. No fouling of the reaction apparatus was observed.

EXAMPLES 61-65 PRODUCTION OF SUPPORTED COCATALYST

In a dry box under nitrogen, "Grace Davison XPO-2402 silica" (spray dried 948 silica dehydrated to 1 mM OH/g) was dissolved in an anhydrous solvent and cocatalyst was added. The resulting mixture was agitated by shaking for a given reaction time. The solid supported cocatalyst was then filtered, washed several times with the same solvent and finally with pentane and dried under vacuum. Al content was measured using ICP analysis. See Table 6 for details of the supported catalysts. Elemental imaging using scanning electron microscopy showed that in the cocatalysts in Table 6, aluminum is evenly distributed throughout the silica particles. TABLE 6

EXAMPLES 66-71 PRODUCTION OF SUPPORTED CATALYST

Inside a drying cabinet in a nitrogen atmosphere, the respective cocatalyst carrier of Examples 61-65 was weighed into a single glass ampoule and a solution of the nickel compound:

in anhydrous toluene. The resulting mixture was agitated by shaking for 60 minutes. The solid supported catalyst was filtered off, washed several times with toluene and finally with pentane and dried under vacuum. The Al and Ni contents were measured by ICP analysis. The results are summarized in Table 7. TABLE 7

a commercially produced by Grace Davison using MAO

b after filtration and washing, a certain color remained in the solution

EXAMPLES 72-77 ETHYLENE POLYMERIZATIONS IN SLURRY

Inside a dry box, the supported catalyst of Examples 71-76 was slurried in 5 mL of anhydrous cyclohexane under nitrogen and drawn into a syringe. The tip of the needle was capped and the syringe was removed from the dry box. A 100 mL Parr® stirred reactor was dried under vacuum at 150°C and after cooling, the slurry solvent (50 mL of anhydrous 2,2,4-trimethylpentane) was added. The reactor was purged with dry nitrogen and the catalyst was added via an addition port. The port was closed and stirring was started and the reactor was brought to 50°-52°C. Ethylene (1.0 MPa) was introduced from a high pressure vessel and the polymerization reaction was allowed to proceed for 30 minutes at 55°C. The ethylene was then vented. and the reaction was quenched by addition of methanol. The product was filtered, washed thoroughly with methanol/10% HCl solution and then with methanol and finally with acetone and dried under vacuum at 60ºC. The results are shown in Table 8. TABLE 8 a

a Al : Ni ratio determined by ICP analysis

TO# = Mole consumption of ethylene/mole nickel

Tm = melting point (determined by DSC)

Branching determined by 1HNMR (120ºC,TCE)

b GC analysis of the exhaust gas revealed the presence of significant amounts of tert-2-butene

c strong ethylene uptake relative to polymer yield indicates that butenes were produced

Claims (8)

1. A catalyst for the polymerization of olefins, prepared by a process comprising: (a) Contact at a temperature of -100ºC to ±200ºC: a first compound W which is a neutral Lewis acid capable of splitting off either Q⁻ or S⁻ to form WQ⁻ or WS⁻, provided that the anion formed is a weakly coordinating anion; or a cationic Lewis or Bronsted acid whose counterion is a weakly coordinating anion; a second compound of the formula: and a first polymerizable olefin, in which formula is: M Ni or Pd; R² and R⁵ are each independently hydrocarbyl or substituted hydrocarbyl, provided that the carbon atom attached to the imino nitrogen has at least two carbon atoms attached thereto; R³ and R⁴ are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl, or R³ and R⁴ are taken together hydrocarbylene or substituted hydrocarbylene to form a ring; Q is alkyl, hydride, chloride, iodide or bromide; and S alkyl, hydride, chloride, iodide or bromide; as well as (b) isolating a polymer formed in (a) without exposing the polymer to a substance or condition that would deactivate the active polymerization sites present in or on the polymer. 2. A catalyst according to claim 1, wherein the first polymerizable olefin is ethylene. 3. A catalyst according to claim 1, wherein the first polymerizable olefin is cyclopentene. 4. A catalyst according to any one of claims 1 to 3, wherein M is nickel. 5. A process for the polymerization of olefins comprising the steps of contacting the catalyst according to any one of the preceding claims 1 to 3 with a second polymerizable olefin at a temperature of -100°C to +200°C. 6. The process of claim 5 wherein M is nickel. 7. The catalyst of claim 5 wherein the first polymerizable olefin is ethylene. 8. The catalyst of claim 6 wherein the first polymerizable olefin is ethylene.